An electronic apparatus (a mobile terminal which will hereinafter be termed a smartphone and other equivalent mobile apparatuses) having portability, instanced by a tablet Personal Computer (PC) or a smartphone that has been widely used, is connected to an accessory apparatus like a cradle or a docking station in many cases. The smartphone and the accessory apparatus are electrically connected by bringing contacts of connectors provided respectively thereon into a contact state. Such being the case, there is proposed a method of checking whether the smartphone and the accessory apparatus are connected or not yet connected (e.g., Patent Document 1).